Fire alarm



Oct. 5, 1937. E, SARCIONE 2,094,825

FIRE ALARM Filed May 21, 1935 INVENTOR ATTORNEY Patented Oct. 5, 1937 UNITED STATES PATENT OFFICE 1 Claim.

This invention relates to electric fire alarms and has for an object to provide an extremely simple and durable circuit closer which will be positivein operation and will include an exposed fusible strip and switch contacts connected to the strip and including a spring pressed movable contact which is adjustably connected to the strip and holds the strip under tension so that upon rupture of the strip due to fire in proximity to the strip, the switch contacts will be sharply closed to close the alarm circuit.

A further object is to provide a circuit closer which may be easily applied to a horizontal or vertical support in the room or other locality to be protected, and will include a movable rod carrying a switch contact in the nature of a cross arm which bridges fixed switch contacts arranged oneither side of the rod in a casing or housing, and is held in tight engagement with the fixed contact by a spring which encircles the rod and is held under tension between a nut on the rod and a transverse partition in the housing, the partition serving to separate the housing into two compartments one of which houses the switch contacts only and the other of which houses the spring so that danger of a short circuit will be positively prevented.

With the above and other objects in view the invention consists of certain novel details of construction and combinations of parts hereinafter fully described and claimed, it being understood that various modifications may be resorted to within the scope of the appended claim without departing from the spirit or sacrificing any of the advantages of the invention.

In the accompanying drawing forming part of this specification,

Figure 1 is a front elevation of a fire alarm circuit closer constructed in accordance with my invention.

Figure 2 is a longitudinal sectional view of the circuit closer.

Figure 3 is a detail cross sectional view taken on the line 33 of Figure 1.

Figure 4 is a diagrammatic view showing the circuit closer and circuit wires connecting the alarm devices thereto.

Referring now to the drawing in which like characters of reference designate similar parts in the various views, l0 designates a cylindrical housing which may be attached to a vertical or horizontal support by means of screws l l. A circular cover l2 closes the front of the housing and is removably secured in position by means of screws I3 passed through the cover and into lugs I 4 carriedby the cylindrical wall of the housing.

A transverse partition l5 extends diametrically across the housing and divides the housing into two substantially equal compartments.

A rod l6 extends perpendicular to the partition and is slidably mounted in the partition by means of a bushing IT. The rod projects outwardly through the cylindrical wall of thehousing and is slidably fitted in said wall by means of a bushing l8. A helical spring I9 surrounds the rod within the housing, one end of the spring bearing upon the bushing l! and the opposite end bearing upon an adjusting nut 20 by means of which the tension of the spring may be regulated. A cross arm 2| is fixed to the rod on the opposite side of the partition from the spring, by means of a set screw 22 and forms a movable switch contact.

A pair of fixed switch contacts 23 are secured to the rear wall of the casing by means of nuts 2| to turn on the rod. Thus the positive opera- U tion of the circuit closer is assured at all times.

A fusible strip 21 of celluloid or other material is provided at opposite ends With eyes 28 and 29 one of which is provided with a constricted neck 30 and beyond the neck terminates in a rounded head 3|. An angle iron bracket 32 is provided in one arm with spaced fingers 33 between which the neck 30 is received, these fingers being bowed downwardly as shown best in Figure 2 and forming seats for the rounded head 3| of the eye 28. The other leg of the bracket may be fastened securely to the support 34 towhich the housing 10 is secured, a screw 35 or similar connector being passed through the leg and into the support as shown.

The other eye 29 of the fusible strip is provided with a yoke 36 having a transverse bridge 3! connecting the branches of the yoke and provided with an opening to receive a stud 38 formed integral with the head of an adjusting described rod [6. By turning the adjusting screw 39 the slack may be taken out of the fusible strip and further rotation of the screw will advance the rod "5 against the tension of the spring I9 and render the fusible strip taut..

The conductor wires 4| enter the casing 10 through an opening in the cylindrical Wall thereof and are directed on opposite sides of the spring I9 and terminally connected to the fixed contacts 23 by nuts 42. It will be observed that the Wires M and the spring I9 are housed on one side of the partition [5 while the switch contacts 2| and 23 are housed on the opposite side of the partition. Thus accidental short circuits are prevented since the switch contacts are confined in a separate compartment away from the metal spring or the wires 4|.

By referring to Figure 4 it will be seen that the circuit closer is connected in series with a transformer 43, an audible alarm 44 and a visible alarm 45 as usual, so that upon a fire starting in the vicinity of the circuit closer the fusible strip will be ruptured and permit the circuit closer to close the circuit and energize the alarm devices.

From the above description it is thought that the construction and operation of my invention will be fully understood without further explanation.

What is claimed is:

In a fire alarm device, a cylindrical housing, a circular cover for the front of the housing, a partition extending diametrically across the housing, aligned insulating bushings in the partition and in the cylindrical wall of the housing, a rod slidably mounted in said bushings and extending exteriorly of the housing, a fusible strip adjustably secured to the rod outside of the housing and adapted to be anchored stationary at the free end, an expansion spring sleeved on the rod and bearing against the bushing in the partition for moving the rod endwise through the partition when the fusible strip melts, a transversely disposed switch contact adjustably mounted on the rod on the opposite side of the partition from the spring, a pair of switch contacts carried by the rear circular wall of the partition and insulated therefrom and having stops on the ends, said transverse switch contact being adapted to bring the fixed switch contacts and close an alarm circuit, and circuit wires entering the circular wall of the partition adjacent to said spring and passing through the partition, said circuit wires being terminally secured to respective ones of said fixed switch contacts.

EDWARD SARCIONE. 

